Exhibit 4.20


 


THIS SECURITY HAS NOT BEEN
REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION
FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE
OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION
FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE
STATE SECURITIES LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL
BE REASONABLY ACCEPTABLE TO THE COMPANY.


 


Original Issue Date: April XX, 2018


 


Principal Amount: $XXX,000.00


Purchase Amount: $XXX,000.00


 


SERIES
G 15% ORIGINAL ISSUE DISCOUNT 


Senior
secured PROMISSORY NOTE


Due
June 15, 2018


 


THIS Series G 15% Original
Issue Discount Senior Secured Promissory Note is one of a series of duly authorized and validly issued Series G 15% Original Issue
Discount Senior Secured Promissory Notes of Summit Semiconductor, Inc., a Delaware corporation (the “Company”),
having its principal place of business at 6840 Via Del Oro, Ste. 280, San Jose, CA 95119, designated as its Series G 15% Original
Issue Discount Senior Secured Promissory Note due June 15, 2018 (this Series G 15% Original Issue Discount Senior Secured Promissory
Note, the “Note” and, collectively with the other Notes of such series, the “Notes”).


 


FOR VALUE RECEIVED, the
Company promises to pay to XXXXXXXXXX or its registered assigns (the “Holder”), or shall have paid pursuant
to the terms hereunder, the principal sum of XXXXXXXXXX Dollars ($XXX,000.00) on June 15, 2018 (the “Maturity Date”)
or such earlier date as this Note is required or permitted to be repaid as provided hereunder, and to pay interest to the Holder
on the then outstanding principal amount of this Note in accordance with the provisions hereof. This Note is subject to the following
additional provisions:


 


Section 1.          Definitions.
For the purposes hereof, in addition to the terms defined elsewhere in this Note, (a) capitalized terms not otherwise defined herein
shall have the meanings set forth in the Subscription Agreement (as defined below) and (b) the following terms shall have the following
meanings:


 


“Affiliates”
shall mean, with respect to any specified Person, any other Person that, at the time of determination, directly or indirectly through
one or more intermediaries, controls, is controlled by or is ‘under common control with such specified Person.


 




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“Bankruptcy
Event” means any of the following events: (a) the Company or any Significant Subsidiary (as such term is defined in Rule
1-02(w) of Regulation S-X) thereof commences a case or other proceeding under any bankruptcy, reorganization, arrangement, adjustment
of debt, relief of debtors, dissolution, insolvency or liquidation or similar law of any jurisdiction relating to the Company or
any Significant Subsidiary thereof, (b) there is commenced against the Company or any Significant Subsidiary thereof any such case
or proceeding that is not dismissed within sixty (60) days after commencement, (c) the Company or any Significant Subsidiary thereof
is adjudicated insolvent or bankrupt or any order of relief or other order approving any such case or proceeding is entered, (d)
the Company or any Significant Subsidiary thereof suffers any appointment of any custodian or the like for it or any substantial
part of its property that is not discharged or stayed within sixty (60) calendar days after such appointment, (e) the Company or
any Significant Subsidiary thereof makes a general assignment for the benefit of creditors, (f) the Company or any Significant
Subsidiary thereof calls a meeting of its creditors with a view to arranging a composition, adjustment or restructuring of its
debts or (g) the Company or any Significant Subsidiary thereof, by any act or failure to act, expressly indicates its consent to,
approval of or acquiescence in any of the foregoing or takes any corporate or other action for the purpose of effecting any of
the foregoing.


 


“Board of Directors”
means the board of directors of the Company.


 


“Business
Day” means any day except any Saturday, any Sunday, any day which is a federal legal holiday in the United States or
any day on which banking institutions in the State of New York are authorized or required by law or other governmental action to
close.


 


“Change
of Control Transaction” means the occurrence after the date hereof of any of (a) an acquisition after the date hereof
by an individual or legal entity or “group” (as described in Rule 13d-5(b)(1) promulgated under the Securities Exchange
Act of 1934, as amended) of effective control (whether through legal or beneficial ownership of capital stock of the Company, by
contract or otherwise) of in excess of fifty percent (50%) of the voting securities of the Company, provided that the foregoing
shall not apply to acquisitions by the Holder or any of its Affiliates, (b) the Company merges into or consolidates with any other
Person, or any Person merges into or consolidates with the Company and, after giving effect to such transaction, the stockholders
of the Company immediately prior to such transaction own less than sixty-six percent (66%) of the aggregate voting power of the
Company or the successor entity of such transaction, (c) the Company sells or transfers all or substantially all of its assets
to another Person and the stockholders of the Company immediately prior to such transaction own less than sixty-six percent (66%)
of the aggregate voting power of the acquiring entity immediately after the transaction, (d) a replacement at one (1) time or within
a three (3)-year period of more than one-half of the members of the Board of Directors which is not approved by at least one of
those individuals who are members of the Board of Directors on the Original Issue Date (or by those individuals who are serving
as members of the Board of Directors on any date whose nomination to the Board of Directors was approved by one of the members
of the Board of Directors who was a member on the date hereof), or (e) the execution by the Company of an agreement to which the
Company is a party or by which it is bound, providing for any of the events set forth in clauses (a) through (d) above.


 




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“Event
of Default” shall have the meaning set forth in Section 4(a).


 


“Mandatory
Default Amount” means the payment of (i) 150% of the outstanding principal amount of this Note and (ii) accrued and unpaid
interest hereon, in addition to the payment of all other amounts, costs, expenses and liquidated damages due in respect of this
Note.


 


“New
York Courts” shall have the meaning set forth in Section 5(d).


 


“Note
Register” shall have the meaning set forth in Section 2(a).


 


“Original
Issue Date” means the date of the first issuance of the Note, regardless of any transfers of the Note and regardless
of the number of instruments which may be issued to evidence such Note.


 


“Person”
shall mean any natural person, general or limited partnership, corporation, limited liability company, limited liability partnership,
firm, association or organization, trust or other legal entity.


 


“Securities
Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.


 


“Subscription
Agreement” means the Subscription Agreement, dated on or about the date hereof, between the Company and the original
Holder, as amended, modified or supplemented from time to time in accordance with its terms.


 


Section 2.           Original
Issue Discount; Prepayment


 


a)         Original
Issue Discount. The Company acknowledges and agrees that this Note has been issued at an original issue discount. No regularly
scheduled interest payments shall be made on this Note. All payments hereunder will be paid to the Person in whose name this Note
is registered on the records of the Company regarding registration and transfers of this Note (the “Note Register”).


 


b)         Optional
Prepayment. At any time upon ten (10) days written notice to the Holder, the Company may prepay any portion of the principal
amount of this Note and any accrued and unpaid interest. If the Company exercises its right to prepay the Note, the Company shall
make payment to the Holder of an amount in cash equal to the sum of (i) the then outstanding principal amount of this Note and
(ii) the accrued and unpaid interest on such outstanding principal amount.


 




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Section 3.           Registration
of Transfers and Exchanges.


 


a)         Different
Denominations. This Note is exchangeable for an equal aggregate principal amount of Notes of different authorized denominations,
as requested by the Holder surrendering the same. No service charge will be payable for such registration of transfer or exchange.


 


b)         Investment
Representations. This Note has been issued subject to certain investment representations of the original Holder set forth in
the Subscription Agreement and may be transferred or exchanged only in compliance with the Subscription Agreement and applicable
federal and state securities laws and regulations.


 


c)         Reliance
on Note Register. Prior to due presentment for transfer to the Company of this Note, the Company and any agent of the Company
may treat the Person in whose name this Note is duly registered on the Note Register as the owner hereof for the purpose of receiving
payment as herein provided and for all other purposes, whether or not this Note is overdue, and neither the Company nor any such
agent shall be affected by notice to the contrary.


 


Section 4.           Events
of Default.


 


a)         “Event
of Default” means, wherever used herein, any of the following events (whatever the reason for such event and whether
such event shall be voluntary or involuntary or effected by operation of law or pursuant to any judgment, decree or order of any
court, or any order, rule or regulation of any administrative or governmental body):


 


		i.	any
                                         material default in the payment of (A) the principal amount of any Note or (B) interest,
                                         liquidated damages and other amounts owing to a Holder on any Note, as and when the same
                                         shall become due and payable (whether on the Maturity Date or by acceleration or otherwise)
                                         which default, solely in the case of an interest payment or other default under clause
                                         (B) above, is not cured within three (3) Business Days;



 


		ii.	the Company shall fail to observe or perform any other
material covenant or material agreement contained in this Note which failure is not cured, if possible to cure, within the earlier
to occur of (A) five (5) Business Days after notice of such failure sent by the Holder or by any other Holder to the Company and
(B) ten (10) Business Days after the Company has become or should have become aware of such failure;



 


		iii.	a material default or material event of default (subject
to any grace or cure period provided in the applicable agreement, document or instrument) shall occur under (A) any of the Transaction
Documents (as defined in the Subscription Agreement) or (B) any other material agreement, lease, document or instrument to which
the Company or any Company subsidiary is obligated (and not covered by clause (vi) below), which in the case of clause (B) is
not being disputed in good faith by the Company;



 




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		iv.	any material representation or material warranty made in
this Note, any other Transaction Documents, or any report, financial statement or certificate made or delivered to the Holder
or any other Holder pursuant hereto or thereto shall be untrue or incorrect in any material respect as of the date when made or
deemed made;



 


		v.	the Company or any Significant Subsidiary (as such term
is defined in Rule 1-02(w) of Regulation S-X) shall be subject to a Bankruptcy Event;



 


		vi.	the Company or any Company subsidiary shall default on
any of its material obligations under any mortgage, credit agreement or other facility, indenture agreement, factoring agreement
or other instrument under which there may be issued, or by which there may be secured or evidenced, any indebtedness for borrowed
money or money due under any long term leasing or factoring arrangement that (a) involves an obligation greater than $50,000,
whether such indebtedness now exists or shall hereafter be created, and (b) results in such indebtedness becoming or being declared
due and payable prior to the date on which it would otherwise become due and payable (except for the events of default with respect
to those certain Series D Senior Secured Original Issue Discount Convertible Notes and related transaction documents);



 


		vii.	the Company shall be a party to any Change of Control Transaction;



 


		viii.	any formal action knowingly intended to effectuate any
of the foregoing;



 


		ix.	the occurrence of any levy upon or seizure or attachment
of, or any uninsured loss of or damage to, any property of the Company or any Subsidiary having an aggregate fair value or repair
cost (as the case may be) in excess of $100,000 individually or in the aggregate, and any such levy, seizure or attachment shall
not be set aside, bonded or discharged within thirty (30) days after the date thereof;



 


		x.	any monetary judgment, writ or similar final process shall
be entered or filed against the Company, any subsidiary or any of their respective property or other assets for more than $50,000,
and such judgment, writ or similar final process shall remain unvacated, unbonded or unstayed for a period of forty-five (45)
calendar days; or



 


		xi.	the Company does not consummate its initial public offering
by June 15, 2018.



 




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b)         Remedies
Upon Event of Default.


 


		i.	Subject to the cure periods described Section 4(a), if
any Event of Default occurs, then the outstanding principal amount of this Note, plus accrued but unpaid interest, liquidated
damages and other amounts owing in respect thereof through the date of acceleration, shall become, at the Holder’s election,
immediately due and payable in cash at the Mandatory Default Amount.



 


		ii.	After the occurrence of any Event of Default (subject to
the cure periods described Section 4(a)) that results in the eventual acceleration of this Note, the interest rate on this Note
shall accrue at an additional interest rate equal to the lesser of ten percent (10%) per month (one hundred twenty percent (120%)
per annum) after the Event of Default or the maximum rate permitted under applicable law. Upon the payment in full of the Mandatory
Default Amount, the Holder shall promptly surrender this Note to or as directed by the Company. In connection with such acceleration
described herein, the Holder need not provide, and the Company hereby waives, any presentment, demand, protest or other notice
of any kind, and the Holder may immediately and without expiration of any grace period enforce any and all of its rights and remedies
hereunder and all other remedies available to it under applicable law. Such acceleration may be rescinded and annulled by Holder
at any time prior to payment hereunder and the Holder shall have all rights as a holder of the Note until such time, if any, as
the Holder receives full payment pursuant to this Section 4(b). No such rescission or annulment shall affect any subsequent Event
of Default or impair any right consequent thereon



 


		iii.	Subject to the cure periods described Section 4(a), upon
any Event of Default the Series F 15% Senior Secured Note, due June 30, 2018, in the aggregate principal amount of $2,000,000
(the “Candlewood Series F Notes”), issued to Candlewood Structured Credit Harvest Master Fund LP (“Candlewood
Harvest”) and Candlewood Structured Credit Opportunity Master Fund A LP (“Candlewood Opportunity”
and together with Candlewood Harvest, “Candlewood”) by the Company shall immediately be due and payable, including,
without limitation, the entire outstanding principal amount of the Candlewood Series F Notes, all accrued and unpaid interest
thereon, and any other amounts due under the Candlewood Series F Notes. Further, upon any Event of Default, the Candlewood Series
F Notes shall be deemed pari passu with the Series G 15% Original Issue Discount Senior Secured Promissory Notes issued
to Candlewood, in all respects, including, without limitation, the security interests granted to Candlewood under the Candlewood
Series F Notes. For the avoidance of doubt, upon any Event of Default (subject to the cure periods described Section 4(a)), Candlewood’s
claims against the Company shall be deemed senior to any and all claims by the Holder.



 






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Section 5.           Miscellaneous.


 


a)         Notices.
Any and all notices or other communications or deliveries to be provided by the Holder hereunder shall be in writing and delivered
personally, by facsimile, or sent by a nationally recognized overnight courier service, addressed to the Company, at the address
set forth above, or such other facsimile number or address as the Company may specify for such purposes by notice to the Holder
delivered in accordance with this Section 5(a). Any and all notices or other communications or deliveries to be provided by the
Company hereunder shall be in writing and delivered personally, by facsimile, or sent by a nationally recognized overnight courier
service addressed to each Holder at the facsimile number or address of the Holder appearing on the books of the Company, or if
no such facsimile number or address appears on the books of the Company, at the principal place of business of such Holder, as
set forth in the Subscription Agreement. Any notice or other communication or deliveries hereunder shall be deemed given and effective
on the earliest of (i) the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number
set forth on the signature pages attached hereto prior to 5:30 p.m. (New York City time) on any date, (ii) the next Business Day
after the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number set forth on
the signature pages attached hereto on a day that is not a Business Day or later than 5:30 p.m. (New York City time) on any Business
Day, (iii) the second (2nd) Business Day following the date of mailing, if sent by U.S. nationally recognized overnight
courier service or (iv) upon actual receipt by the party to whom such notice is required to be given.


 


b)         Absolute
Obligation. Except as expressly provided herein, no provision of this Note shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of, liquidated damages and accrued interest, as applicable, on this Note
at the time, place, and rate, and in the coin or currency, herein prescribed. This Note is a direct debt obligation of the Company.


 


c)         Lost
or Mutilated Note. If this Note shall be mutilated, lost, stolen or destroyed, the Company shall execute and deliver, in exchange
and substitution for and upon cancellation of a mutilated Note, or in lieu of or in substitution for a lost, stolen or destroyed
Note, a new Note for the principal amount of this Note so mutilated, lost, stolen or destroyed, but only upon receipt of evidence
of such loss, theft or destruction of such Note, and of the ownership hereof, reasonably satisfactory to the Company.


 




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d)         Governing
Law. All questions concerning the construction, validity, enforcement and interpretation of this Note shall be governed by
and construed and enforced in accordance with the internal laws of the State of New York, without regard to the principles of conflict
of laws thereof. Each party agrees that all legal proceedings concerning the interpretation, enforcement and defense of the transactions
contemplated by any of the Transaction Documents (whether brought against a party hereto or its respective Affiliates, directors,
officers, shareholders, employees or agents) shall be commenced in the state and federal courts sitting in the City of New York,
Borough of Manhattan (the “New York Courts”). Each party hereto hereby irrevocably submits to the exclusive
jurisdiction of the New York Courts for the adjudication of any dispute hereunder or in connection herewith or with any transaction
contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents), and hereby
irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to
the jurisdiction of such New York Courts, or such New York Courts are improper or inconvenient venue for such proceeding. Each
party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding
by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the
address in effect for notices to it under this Note and agrees that such service shall constitute good and sufficient service of
process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any other
manner permitted by applicable law. Each party hereto hereby irrevocably waives, to the fullest extent permitted by applicable
law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Note or the transactions contemplated
hereby. If any party shall commence an action or proceeding to enforce any provisions of this Note, then the prevailing party in
such action or proceeding shall be reimbursed by the other party for its attorneys’ fees and other costs and expenses incurred
in the investigation, preparation and prosecution of such action or proceeding.


 


e)         Waiver.
No provision of this Note may be waived, modified, supplemented or amended except in a written instrument signed, in the case of
an amendment, by the Company and the Holder or, in the case of a waiver, by the party against whom enforcement of any such waived
provision is sought. No waiver of any default with respect to any provision, condition or requirement of this Note shall be deemed
to be a continuing waiver in the future or a waiver of any subsequent default or a waiver of any other provision, condition or
requirement hereof, nor shall any delay or omission of any party to exercise any right hereunder in any manner impair the exercise
of any such right.


 


f)           Severability.
If any provision of this Note is invalid, illegal or unenforceable, the balance of this Note shall remain in effect, and if any
provision is inapplicable to any Person or circumstance, it shall nevertheless remain applicable to all other Persons and circumstances.
If it shall be found that any interest or other amount deemed interest due hereunder violates the applicable law governing usury,
the applicable rate of interest due hereunder shall automatically be lowered to equal the maximum rate of interest permitted under
applicable law. The Company covenants (to the extent that it may lawfully do so) that it shall not at any time insist upon, plead,
or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury law or other law which would
prohibit or forgive the Company from paying all or any portion of the principal of or interest on this Note as contemplated herein,
wherever enacted, now or at any time hereafter in force, or which may affect the covenants or the performance of this Note, and
the Company (to the extent it may lawfully do so) hereby expressly waives all benefits or advantage of any such law, and covenants
that it will not, by resort to any such law, hinder, delay or impede the execution of any power herein granted to the Holder, but
will suffer and permit the execution of every such power as though no such law has been enacted.


 




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g)         Remedies,
Characterizations, Other Obligations, Breaches and Injunctive Relief. The remedies provided in this Note shall be cumulative
and in addition to all other remedies available under this Note and any of the other Transaction Documents at law or in equity
(including a decree of specific performance and/or other injunctive relief), and nothing herein shall limit the Holder’s
right to pursue actual and consequential damages for any failure by the Company to comply with the terms of this Note.  The
Company covenants to the Holder that there shall be no characterization concerning this instrument other than as expressly provided
herein. Amounts set forth or provided for herein with respect to payments and the like (and the computation thereof) shall be the
amounts to be received by the Holder and shall not, except as expressly provided herein, be subject to any other obligation of
the Company (or the performance thereof). The Company acknowledges that a breach by it of its obligations hereunder will cause
irreparable harm to the Holder and that the remedy at law for any such breach may be inadequate. The Company therefore agrees that,
in the event of any such breach or threatened breach, the Holder shall be entitled, in addition to all other available remedies,
to an injunction restraining any such breach or any such threatened breach, without the necessity of showing economic loss and
without any bond or other security being required. The Company shall provide all information and documentation to the Holder that
is requested by the Holder to enable the Holder to confirm the Company’s compliance with the terms and conditions of this
Note.


 


h)         Next
Business Day. Whenever any payment or other obligation hereunder shall be due on a day other than a Business Day, such payment
shall be made on the next succeeding Business Day.


 


i)           Headings.
The headings contained herein are for convenience only, do not constitute a part of this Note and shall not be deemed to limit
or affect any of the provisions hereof.


 


j)           Use
of Proceeds. The Company shall use the net proceeds from the sale of the Note for working capital and general corporate purposes.
The Company must receive the consent of at least 50.1% in interest of the Notes then outstanding by the Subscribers prior to withdrawing
the Subscribers aggregate subscription amounts from the escrow account.


 


k)         Secured
Obligation. The obligations of the Company under this Note are secured pursuant to the Security Agreement, dated as of the
date hereof between the Company and the Holder.


 


*********************


(Signature Pages Follow)


 




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IN WITNESS WHEREOF, the
Company has caused this Note to be duly executed by a duly authorized officer as of the date first above indicated.


 


	 	SUMMIT SEMICONDUCTOR, inc.
	 	 	 
	 	By: 	
	 	 	Name: Brett Moyer
	 	 	Title: CEO
	 	 
	 	Facsimile No. for delivery of Notices: 408-362-3431


 




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